How To Manage A Ledge - A case report

Among all the difficulties we encounter during the reconstruction of an incongruous root canal therapy, a very difficult challenge is always represented by overcoming false paths and ledges mistakenly created during the primary treatment(1).

A 26-year-old patient comes to my attention due to a fracture at element 4.7. The patient reports recurrent episodes of pain when chewing in the indicated area. The objective examination immediately reveals signs of inflammation which manifest themselves with strong tenderness upon percussion of the element, carious infiltration of most of the previous restoration and a favorable fracture of the enamel and subgingival and supracrestal dentin. The radiographic examination confirms the previous diagnostic questions and shows inadequate previous root canal therapy in terms of vertical and three-dimensional filling. Apical lesions of both roots are also noted. The perimeter probing of the tooth does not reveal root fractures.

First of all, therefore, we proceed with the removal of the old adhesive restoration and with the cleaning of the carious lesion and, before starting to retreat the tooth, to be sure of the restorability of the element, we proceed with the relocation of the lingual margin(2).

Then we proceed with the disassembling of the chamber portion and, once the canal entrances have been located, we begin to empty the previous filling. This delicate maneuver is tackled easily thanks to 25/06 files and the use of the reciprocation system(3).

Having failed to obtain patency of the distal canal system and given the little time available due to emergency management, the chamber portion is temporarily closed with photopolymerizable PMMA material (radiolucent).

During the second appointment, manually probing the distal canal, I immediately realized the presence of an iatrogenic ledge near a sharp distal curvature typical of this root. I decide to pre-curve k-files of progressive diameters to overcome the obstacle and engage the canal by manually instrumenting it with a delicate "watch winding" movement up to an adequate diameter (30).

The finishing of the mesial canals, once their confluence was proven, was carried out using 30/06.

5.25% NaCl was used throughout therapy to facilitate chemical disinfection and removal of debris. Before obturation, the hypochlorite was activated with ultrasonic tips and, once cleansing was completed, we proceeded with equally activated 17% EDTA washes to remove the smear layer(4).

The obturation technique used to fill the mesial canals was warm vertical

condensation, while the distal canal, since the cone test was not repeatable due to the step, was obturated with the “Squirting Technique”(5).

The case was finalized with a composite overlay.